I played the game.
Just beat the Kanto League, i have to say it was super easy, more easy than previous games.
A little things to make clear:
- Lillie appears in the game, but only to explain what are alolan forms, you have a short battle against alolan Vulpix and that is all
- Zone Safari is almost same as Pokemon Blue and Red, there are more npcs around to explain things about how to capture Pokemons
- Next gyms and cave are silimar like Blue and Red, and they are more easy. Especially Victory Road, you have more npcs healing your team in between
- Your final rival is your Friendly Rival, no Gary. After defeating him, there's a movie ending, it is nice looking, but credits are too long extended (almost 5 minutes)
- Post-game is not much, you can catch Mewtwo, it is super difficult (probably the more difficult battle in the entire game)
- Also, Master Trainers appear around Kanto. They have only one Pokémon with impossible combinations, but they are no difficult, just spam Potions.

I have to say the game is fun, but no a challenge to old players.
I can answer questions, if you don't care about spoilers.
(Sorry about my lack of english, I'm trying my best)